The research described in this proposal is designed to provide new information about both preventive and remedial instructional strategies for children who are either at-risk for the development of reading problems, or who are identified with serious reading disabilities. It is based directly on what is currently known about the environmental and biological factors that are associated with difficulties in learning to read, and it also reflects research based knowledge about effective methods of instruction in reading. Within pre-school, early elementary school, and remedial contexts, the research has three broad aims: 1) to determine which instructional programs, or combination of programs, have the largest immediate impact on word level reading skills and long-term impact on fluency and comprehension skills, of children in the studies; 2) to determine the factors (child characteristics, demographic variables) that are most strongly predictive of individual differences in both immediate and long-term response to the instructional programs we examine; and, 3) to examine the proportion of children within the most effective interventions for whom the intervention was insufficient to support reading growth within the normal range Four multi-year studies will be carried out to accomplish these aims. Experiment 1 examines the relative effectiveness of four treatment combinations to stimulate the growth of emergent literacy skills in a sample of 300 children attending pre-school centers that serve primarily economically disadvantaged children. Experiment 2 will use a second sample of 300 children to examine the outcomes from the most effective intervention from Experiment 1 when it is implemented under three conditions that vary in level of supervision and training/experience of the pre-school teachers. Experiment 3 will evaluate the effectiveness of two types of intensive preventive reading-instruction for 288 first grade children selected because of phonological weaknesses. It will also determine the contextual effects of classroom reading instruction that varies significantly in the degree to which it provides systematic and explicit instruction in alphabetic, or phonetic, reading skills. Experiment 4 will examine the effects of two different approaches to increasing reading fluency and comprehension in a sample of 60 seriously disabled older readers who also receive intensive instruction to increase the accuracy of their word reading strategies. All subjects in these studies will undergo assessments for a variety of emergent literacy and reading outcomes as well as a range of demographic, family, attentional/behavioral, and cognitive factors that will help to understand individual differences in response to the interventions.